1. Field of the Invention
The present invention relates to a detecting gauge, particularly to a detecting gauge with high accuracy.
2. Description of the Related Art
To ensure the quality of the following production, a procedure of detecting the pre-produced specifications must to be executed before a mass production of targets to be detected, such as screws, nuts, and nails. Generally, the targets are detected by a detecting gauge like a curvature instrument, a length instrument, and a concentric instrument.
Referring to FIG. 1, a conventional detecting gauge 1 comprises a machine table 11 and a detecting set 12 disposed on the machine table 11; wherein the detecting gauge 1 is mainly used to detect a target 2 with a short length. The detecting set 12 includes a clamping apparatus 13 disposed on the machine table 11 and capable of clamping a target 2, a detecting apparatus 14 corresponding to the clamping apparatus 13, and a sliding apparatus 15 disposed on the machine table 11. The sliding apparatus 15 includes two parallel sliding shafts 151 disposed on the machine table 11 and a sliding base 152 penetrated by the sliding shafts 151 and capable of being slidably moved on the sliding shafts 151. The detecting apparatus 14 is disposed on a top of the sliding base 152. While detecting, after the target 2 is clamped by the clamping apparatus 13, the detecting apparatus 14 can be moved to a preferable detecting position by moving the sliding base 152 for measuring the specification of the target 2.
However, because the sliding base 152 is penetrated by the sliding shafts 151, the removable sliding base 152 completely contacts the sliding shafts 151 while using the conventional detecting gauge 1 to detect the target 2. Therefore, the resistance between the sliding base 152 and the sliding shafts 151 increases, which causes the sliding smoothness of the sliding base 152 to be lowered and generates the wear of the sliding base 152 and the sliding shafts 151. Consequently, the gap between the sliding base 152 and the sliding shafts 151 is gradually broadened, and the detecting apparatus 14 is relatively affected and apt to sway, thereby lowering the accuracy of data measured by the detecting apparatus 14 and causing the detected data to become imprecise.
Consulting FIG. 2, usually, a target 2 with a longer length is detected by another conventional detecting gauge 1 which still comprises a machine table 11, a detecting set 12, a clamping apparatus 13, a detecting apparatus 14, and a sliding apparatus 15. The detailed components are the same as the previous prior art and herein are omitted. Particularly, this conventional gauge 1 further includes a supporting apparatus 16 disposed on the sliding apparatus 15. The supporting apparatus 16 provides a supporting base 161 disposed on the sliding base 152 and two supporting members 162 juxtaposed on the supporting base 161. Each supporting member 162 includes an axle 1621 projected out of the supporting base 161 and a bearing 1622 sleeved on the axle 1621. While detecting, one end of the target 2 is placed on the clamping apparatus 13 for being pressed by the clamping apparatus 13, and the other end of the target 2 is placed between the bearings 1622 for being measured by the detecting apparatus 14.
However, after using, the conventional detecting gauge 1 still has drawbacks as follows:
1. Generally, a plurality of rollers P shown in FIG. 3 are disposed inside the bearing 1622 of each supporting member 162, and a space S filled with lubricant (not shown) is usually retained in the interior of the bearing 1622 in advance for allowing the rollers P to rotate in the bearing 1622. However, while one end of the target 2 is placed on the bearings 1622 and the other end thereof is pressed by the clamping apparatus 13, the existence of the space S is apt to cause the deviation of the bearings 1622 by the weight of the target 2 itself and the pressing force of the clamping apparatus 13. Under the rotation of the bearings 1622, the target 2 will be deviated or inclined toward different direction by following the rotation. Therefore, the detected data measured by the detecting apparatus 14 becomes imprecise, and then the operator is apt to misjudge the detected data; that is, the operator sitting in judgment on whether the processing data of the target 2 is qualified is affected, which is however adverse to the following mass production.
2. Tolerance exists in most bearings 1622 while manufacturing, consequently, the factors that the bearing 1622 may still be loosely sleeved on the axle 1621 and the space S is retained in the interior of the bearing 1622 could have the adverse influence on the accuracy of measurement of the detecting apparatus 14.
3. Since the target 2 provides one end thereof merely griped by the clamping apparatus 13 and the other end thereof placed on the bearings 1622 by its weight, the longer the length of the target 2 is obtained, the easier the target 2 is affected by an exterior force or the rotation of the detecting procedure and deviated from the supporting apparatus 16 (as dotted line shown in FIG. 4). As a result, the detecting apparatus 14 cannot get the precise detected data of the target 2.